Astronomy Practice Exam

What happens to astronauts and objects inside a spacecraft when in weightlessness?

1. They are anchored to the floor

2. They float due to lack of mass

3. They don't fall to the floor because of their acceleration towards Earth

4. They are not influenced by gravity

The correct answer is: They don't fall to the floor because of their acceleration towards Earth

In a state of weightlessness, astronauts and objects inside a spacecraft are indeed in a condition often referred to as microgravity. This sensation arises because both the spacecraft and its occupants are in free fall towards Earth at the same rate, resulting in a uniform acceleration. As the spacecraft orbits Earth, it continuously falls toward our planet but due to its forward velocity, it travels along a curved path. This creates the environment where everything inside experiences a sensation of weightlessness; they do not experience any resistance against gravity. Thus, they appear to float rather than being 'anchored' or having a lack of mass, which gives the illusion of zero gravity. Understanding this is crucial as it illustrates that they are still influenced by gravity; rather, it's the falling motion of both the objects and the spacecraft together that creates the unique experience of weightlessness.